Concentrator



July 6, 1943- MGLEAN 2,323,557

GONCENTRATOR Filed March 8, 1941 3- Sheets-Sheet l L @T7-DEWEY July 6, 1943. l..-` MCLEAN 2,323,557 CONCENTRATOR Filed March 8, `1941 5 Sheets-Sheet 2 /NL/E/v TD/ m/LE MCLEA/v /ITTURNE July 6, 1943. L. McLEAN 2,323,557

' vcoNoENTmaToR l Filed Mrch 8, 1941 5 sheets-sheet s v Fig. 8.

Patented July 6, 1943 iiliaviNT @FFME 2,323,557 ooNcENrRA'roR Lyle McLean, Portland, Oreg.

Application March 8, 1941, Serial No. 382,439 s claims. (ci. 209-44) This invention relates generally to the mining industry and particularly to a concentrator.

The main object of this invention is to construct a concentrator whereby precious metals may be efficiently recovered by air flotation.

The second object is to construct a concentrator wherein there will occur a natural iiow of materials in which the recovered metals gravitate in one direction while the gangue is moved by air flotation in a different direction toward the end that there will be produced a complete separation of the gangue and metals being recovered.

The third object is to produce a concentrator of the class described especially adapted to the treatment of the finer material due to the fact that all of the gangue is kept in flotation durb ing the concentrating process.

These and other objectsare accomplished in the manner set forth in the following specication as illustrated in the accompanying drawings, in which:

Fig. l is a vertical section through the device.

Fig. 2 is a transverse section taken along the line 2 2 in Fig 1,

Fig. 3 is a plan showing the hopper.

Fig. 4 is a plan of the concentrating section showing the concentrating plate with a portion of the screen removed from above same.

Fig. 5 is a section taken along the line 5-5 in Fig. 6 is a fragmentary end elevation of the concentrator showing the air lines and dust tubes.

Fig. 7 is a fragmentary section taken along the line 'l-I in Fig. 4,

Fig. 8 is a fragmentary section at a much enlarger scale showing the construction of the perforated concentrating plate, its mounting and `the superimposed screen showing a somewhat similar parts I6 which engages the upper edge of the conical inner shell I'l whose innermost portion I3 is cylindrical in form.

The end II terminates in an internally threaded coupling I9 in which is secured the tubular bleeder pipe 26 which extends downwardly through the center of the innermost porti-.on i8 of the inner shell il. 'Ihe shell portion i8 and the bleeder pipe 29 are separated by the spacing collar 2i and the parts secured by means of the set screws 22,

Outside of the member I 5 is an intermediate cylindrical portion 23 which is held in concentric relation with the portion I8 by means of the spacing bushing 24. The cylindrical intermediate portion 23 supports the conical intermediate portion 25 on whose upper edge 26 is secured a ring 2 which supports the perforated plate 23 in cascade fashion above the plate IQ. The plate 28 also slopes downwardly toward the center of the device and is spaced vertically from the plate i6 by means of a spacing ring 29 whose underside is provided with radial slots 39.

Outside of the portion 23 and spaced therefrom, is a cylindrical outer portion 3| which is spaced from the portion 23 by means of a bushing 32 and secured thereto by means of the screws 33. In the upper end of the member 3I is disposed the conical portion 34 whose upper end 35 has mounted thereon the outermost perforated plate 35 whose lower end rests upon the ring 3l which in turn rests upon the plate 28 and is notched similarly to the ring 29.

Disposed above the plates I9, 28 and 36 is a screen 38 which is supported by the concentric rings 39, 49 and 4I which in turn are united by the radial spokes 42 whose outer ends 49 rest upon the ring 44 which forms a wall around the outside of the outermost screen plate 36 The screen 39 slopes downwardly toward the central ring 39 which is directly above the opening 45 in the coupling I9.

Within the coupling I9 is disposed a head 46 whose perforated top 4l occupies the opening in the ring 39. The radial arms 48 on the head 46 facilitate the rotation of the head and form a support for the ring 39.

o The perforated head 46 is connected by means of the airpipe 49 to the pipe 50 which contains the control valve 5I. The pipe 5D is connected to the air manifold pipe 52 which is connected by means of the pipe 53 to a suitable air supply (not Shown).

The manifold 52 is provided with an outlet pipe 54 including a valve 55 and a connection 56 by means of which air is admitted through the openings 51 to thespace 58. That it provides a supply of air to the perforated plate I0.

The manifold 52 is also provided with an out,- let pipe 59 including a control valve 69 and a connection 6I which admits air through the openings 62 to the space 63 under the plate 28.

The manifold pipe 52 is also provided with an outlet pipe 64 including the control valve 55 and connection 66 to which air is admitted through the hole 6l to the space 68 directly under the plate 35.

It will be noted that the plates i9, 28 and 36 are in cascade relationship and that the grooves 30 permit streams of air to be blown radially across the plates 28 and I0 in an inward direction thereby insuring against the materials from coming to rest upon the surface of the plates between the openings 69 thereof.

ln order to provide a controlled supply of material there is provided a hopper 'Hl having an inverted conical spreader 'il adjustably mounted on the threaded spindle l2 which is supported by the spokes 13 disposed across the opening i4 oi the hopper TG. It is desirable to provide the wings l5 on the spreader 'il to facilitate the rotation thereof and also to provide a clamping nut 76 to hold the spreader 'll in a desired position. A slidable gate 'll is provided under the opening ifi to completely or partially cut off the supply of materials passing out of the hopp The parts thus far described are held in their desired relationship by means of the upright supporting frame "i8 and the diagonal member i9 together with the horizonal tie members 88.

The outlets Si, 82 and 83 are connected by the pipes 84, 85, and BS to the valves 8l, 88, and 89 to which are connected the dust catchers 99, 9i, and 92 whose lower ends are preferably closed by the caps 93 in order to remove the dust therefrom.

The operation of this form-of the device is as follows:

Assuming that a supply of material 94 is contained within the hopper 16 and this material is permitted to iiow downwardly through the opening 'i4 under the control of the spreader 'Il and the gate 'l, as the material falls upon the screen 3S, air is permitted to flow from the manifold 52 through the perforated plates lll, 23 and 35 in a manner to cause a violent bubbling or boiling action in which the material is made to dance continually upon the screen. The smaller, heavier particles pass through the screen 38 onto the plates lll, 28 and 36 where they continue to be agitated and the heavier metallic particles are worked downwardly by gravity while the lighter gangue is carried upwardly and outwardly by the air current.

As the materials on the plates lil, 28 and 36 are worked toward the central opening and descend into the bleeder pipe 28, they are gradually concentrated and caught in the pipe 28 from which they are withdrawn by removing the cap 95.

It will be noted that the head 4B is perforated on its upper side and air from the pipe 4S keeps the material above the head 4S in constant agitation.

It will be observed that some dust falls through the plates lll, 28 and 36 and falls to the lower end of the respective compartments from whence it is carried into the dust catchers 90, 9| and 92 by inertia since the air coming from the connections 56, GI and 66 moves this material hori- :gntally and since the catchers are capped, the air cannot pass into the traps but the inertia of the solids causes the solids to continue in a horizontal direction while the air itself turns upwardly,

In Fig. 8, which is a slightly modified form of the device, the parts are identical with that previously described except that a screen 96 covers the lowermost plate I8-A and the plate 28--A discharges directly upon the screen 96 which is spaced from the plate I -A at its outer edge by means of the ring 2S--A.

In this form of the device, the ring 29--A is provided with radial slots .3Q-A through which air from under the plate 28-A is directed radially toward the center of the device thereby discouraging any of the particles from coming to rest between the openings E39-A.

Above the lowermost end of the plate 28-A is disposed the circular ring Sl whose lower edge 98 is held above the plate 28-A by means of the dowel pins GS. The operation of this form of the device is very similar to that previously described.

As shown in Fig. 7, all of the material is kept in a continuous state of agitation until the concentrates pass downwardly into the bleeder pipe 28 or the gangue is displaced by the incoming material and the air flotation.

The member 3l projects through the inclined plate ll which serves to discharge the waste materials from the machine.

The sides lill and |02 extend above the top of the screen 38. The members |98, ll, and m2 are supported by the members 'i8 and 8D.

I claim:

l. In a concentrator, the combination of a perfo-rated plate whose top surface slopes downwardly toward a central point, a bleeder pipe adapted to draw materials from said central point, an air pipe within said bleeder pipe having a perforated, upwardly discharging air nozzle thereon constituting a cover for the upper end of said bleeder pipe and spaced from the inlet of the bleeder pipe and affording a passageway thereto around the rim thereof, means for causing air to pass upwardly through said perforated plate and a screen over said perforated plate adapted to remove from the materials deposited on said plate the oversized materials which are discharged as gangue.

2. A concentrator of the class described having in combination a plurality of concentric compartments having perforated plates across the upper end thereof, the top side of said plates sloping downwardly toward the center of the innermost compartment, means for delivering air to each of said compartments for the purpose of agitating the materials above same, the innermost compartment having an air supply pipe therein provided with an upwardly discharging air nozzle at its upper end forming an elevated cover for the uppermost end of the innermost compartment, which innermost compartment serves as a bleeder pipe, a dust trap formed at the lower end of each of said compartments from which dust may be withdrawn, and means for withdrawing concentrates from the lower end of said bleeder pipe.

3. A concentrator of the class described having in combination a perforated screen having its top side sloping downwardly toward the center thereof and having an outlet opening at the lowermost central point, a plurality of compartments formed under said screen through which governed quantities of air may be delivered upwardly through the various screen portions above their respective compartments, a bleeder pipe on the under side of said screen communicating with said central opening and an air spraying head mounted over said opening and having its edges spaced from said screen, and a coarse screen over Said first mentioned screen sloping downwardly t0 the rim of said air spraying head and spaced above said first mentioned screen.

LYLE MCLEAN. 

